ANTI SEA EROSION

Coastal length of
Kanniyakumari
district along Arabian Sea is 59 km and along Bay of Bengal is 11 km. RMS
walls are almost constructed in entire length of sea shore of Kanniyakumari
district which is comparatively & densely populated district in Tamilnadu and
has valuable lands with roads along shoreline

RMS walls are rubble mound flexible
breakwater structures tends to settle down continuously due to scouring erosion.
Moreover the stability of interlocking of heavy armour stones have been broken
by knocking/impact of huge wave action during southwest monsoon period
(May-September). Hence reformation of the existing RMS walls in sinked portions
and reconstruction of RMS walls in the washed-off portions are essential. Latest
approved drawing in vulnerable reach from Colachel to Poothurai is also
furnished.

Groynes are proposed to prevent
heavy erosion indirectly by depositing the beach sand carried by littoral drift
parallel to the seashores (long shore sediment transport );Halting facility for
fishing boats will additionally be created on eastern side due to tranquility
condition, since impact of waves due to sea tides into the lands will be reduced
by the projected head of Groins.

Anti Sea
Erosion works are done in Kanniyakumari district for more than 30 years under
state fund, HUDCO fund, 12 th finance commission and now
under 13 th finance commission for which details are separately
be enclosed.

Total value of Anti sea erosion
works executed in Kanyakymari district from 2003 up to 31- 03- 2012 are Rs.
30.45 crores for RMS walls and Rs. 40.97 crores for Groynes. Total value of
Anti sea Erosion Works in Kanyakymari district under 13 th
finance commission is Rs. 24.83 crores.

Non-proper and timely
Non–maintenance of RMS Walls during the past years leads to heavy
damages/failures. A major hurdle in maintenance will be non-availability of
equipment (like cranes) for replacing the damaged/displaced armour units (of
about 2 ton weight).

Annual maintenance cost
of RMS walls for 2 km length for every year in Kanniyakumari District is worked
out (at the rate of 2800 ton armour stones per 100 m length) as Rs. 2.73
crores which is required for maintaining the required profile of RMS walls and
also for emergency maintenance works during huge tides. Since rubble mound
structures are continuously readjusted and displaced due to wave motion, the
detailed working estimate for individual places/locations will be prepared after
getting administrative sanction from Government as per actual during execution.

List of proposals for 27 groynes, 19 RMS walls and 2 training walls for Rs. 250
crores under TN VISION 2023 are also submitted for executing in 13 th
finance commission, state fund, Japan aid, NABARD and the next 14 th finance
commission.

Since IIT- Madras has
given the consultancy report to Tamilnadu Government on Groyne-Field CONCEPT
along Arabian coast (i.e) constructing a series of groynes and the cost of
groyne per 100 M. length is very high of about Rs. 5 crores on comparing RMS
wall cost is about Rs.40 Lakhs per 100 M. length, Groynes & RMS walls are
constructed based on the availability of funds.